Visible index sheet



Oct. 13, 1931. c, BlNGHAM 1,827,638

VISIBLE INDEX SHEET Filed June 29. 1929 2 Sheets-Sheet 2 Q i l- INVENTOR FREDERICK C.BINGHAM JM m ' Patented Oct. 13, 1931 P N OFFICE top or bottom edge is desired. ,1

vIsnaLE mnnx sm'r V Application nled June 29,

" This invention relates to; reinforced ,loose sheets and is especially well adapted for use in prong binders in which visibility of the one object of the invention'is to provide a less bulky and-a more economical reinforced sheet than those heretofore known. In'the drawings" Y Figure 1 shows a planview of part of a 's heet',"rnade according to my invention, in-

d gbi ff Figures is a view similar to -Fig re 1, but shows'the'sheet in a'di fierent position in the serte'dj upon the pr'ongs' of a partially open prong binder,f 1

F'gure 3 is a plan view of a portion ofone side of an 'open prongbinder, in which a number of the improved sheets are filed with a margin of "each-visible, g

longitudinal section' through the sheets on the line 4'4 of 'Fig.- 3, looking in the direction-ofthe arrow. One side of the binder is shownywith the prongsinclose'd position. 1 The improved sheets are adapted for use in prdngbinders of the well-known type in whichalternate prongs are borne by opposite Sides: ofthe binderwy 1 Sheets used for visible"filing' in' prong binders usually contain'aplurality of perforations; In :order'to'provide for varying amounts of overlap, theperforations of the sheets are" commonly placed closer together than are the prongs'of thebinder. For example in a given length of'the sheet there may be twice as many perforations as there are prongsonthe samellength of binder.

.1 When" the :binder is closed, more than two prongs Y are: normally threaded into perforations in each sheet,-at least one prong from V oneihalf-ofithe binder, and least two prongs from theother'half. I ..,-It is common experience that perforated sheetsinany prongbinder are peculiarly sub- ]ect tostrainand the' perforations 'are liable to". tear; oufi'so; that the: sheets can no longer beretained"inithe binderu' T I To avoid this'r'nutilati'o'n'and to strengthen the sheet,-.it has been common to use reinforce ments f. various kinds. 2'1

1929. Serial No. 374,868.

Thetype of reinforcement heretofore employed 111 sheets to be used in prong binders for visible filing, has been a reinforcement extending the entire length ofthe side of the sheet containing the perforations.

The inventor has observed, however, that there is little or no strain 'on the sheet at the prongs intermediate the ends of the sheet, but

that practically all the strain is exerted at the prong which is threaded into the sheet nearest each end thereof.

As-point ed out above there are usually more'perforations inthe sheet than the sum of the prongs from both sides of the binder which will pass through thatsheet.

. The inventor has discovered that in a binder of the type described, if reinforcement is placed around only a few final perforations at each end of the series, the prong threaded into the perforation nearest each end of each sheet will, when the binder is closed, be surrounded by'reinforcement. That this would be the case is not obvious in threading the sheets upon the prongs of the open binder.

In the binder 10 illustrated in the drawings there are series of the usual curved prongs 11 and 11a mounted on the opposite sides 12 and 13 of the binder, in alternating relation.

Loose sheets 15 contain a eries of perforations 16' along one side 17 ofthe sheet ad a.- cent its edge, the perforations belng spaced apart uniform distances from'center to center. The perforated side 17 is at right angles to the margin 18which is visiblewhen the sheets are filed in overlapplng relat on.

' In standard prong binders the prongs are customarily spaced apart multiples of of an inch from center to center. For this reason it is convenient to space the perforatlons 16 at uniformiintervals of of an inch from c.,-micnnn, or NEW ronmn. Y., assronon 'IQ 300mm & rmsn conii i run, or, rmw ronx, .N. Y.,A conromrron or mew YORK tions. For use the standard typeof prong:

binder it is suificient to have'th'e reinforcement 19 surround the final perforation 16a and the next-to-last perforation 16?) at each end'of the side 17 In anyrnpng binde n w i h thepx ngs meme welcome: a meltipl ei he unit of linear measurement by which the perforations in the sheet are spaced apart, and

in' the-' distanee between succeeding prongs is unifer-m,-thelength ot-the reinforcement may be such as to include one lesshole than the number required to receive two suc- When thesheetsfare filed;i 10ver1apping rela ion-wi h amargii .Q e h isf' y shown ieiFigiire -3 s me@ t e she tswil (upon the prongs of wQIgkfi-i side. of the'hinder in the pesigtion semen-Figure Qthers iwil leat the same time'he inserted the position sh0Wn-in1Figiu-re :2, andfsti-l-l ethers-inother positions. :Yet ever-yinlettuce, when the-hinder-is closed therewill heap onig inset-ted inte'ioneef thereinferced holes of eachlendnfthe i w 'lhe' ateinfomement may be fifipapentehtile p 3 mehtat-eaeh.endtifsaidcperforated side, each .materia1',fcr anysuitableesubmancew s V Makingieach ileinforcenient 119 in ne piece. u "or. more is immense z-a sa'yingof labor-is -=Reinforcing only' the portions of efiected by, making it in one piece.

' 'bfa'the sheetsiirronndingathe lastfwThbies at -eaeh.;-end lefl'ects 'a "great saying in- 'i'iein 'forcingmaterialiand -'a.dhesime for apply ing same. i Reinforcing thelsidei1? 7 only around the-few extreme holes at each endlha s .the additional advantage ofrincreasingf the cap acity .ofthe binde r. 'Atthe middle (ifithe binder,v the thickness of-the bundle of sheets is increased-by the reinforcement; only half hr fless, .;insteadofiheing doubled as is; the

case when the 'entire edge is reinforced. For example, 111 Figure 4 a? longitudinal section is shown bf eightrofthe improved sheets filed in- 'aprong binder, with: a margin 18 of each V visibief X andYxarepoints wheret'hewsection p'asses througli all" eight sheets. .Inrthe ordinary. reinforced sheets-, where a; rein- I forcement extending} the length ,of the perforated side is used, thez-thicknessiiit -'X or Y- would bedo uble' the thickness ofthe un -reinforced portlons ofthe-same number of sheets 7 assumingthereinforcing material is of the r at same thickness as. the sheet. itself),or. sixteen:

times the thickness: of a single iunrreinfo d sheet, :Usingith'eimproved Sheets, on the other hand, at'Y'there is no increment-thick f ness'tlo'ver that of the iuiereinforced body" of the sheets, While htEX," which is the -point, of

"nessof-the sheet alone.

PIG Z': 31:: I :J p 1 3. pmng binderfihawwing successive time's the thickness of :the single un-reinforced sheet, instead of sixteen times.

Iclaim: 1 l; A sheet for prong binders,'having a series of perforations adjacent one edge, the

F dera i s Spa e apart w p fiance tee teeter, ajndiliagwing a reinforcement surrounding onlythe two extreme perforations at each end of the series, the thickness ofthe reinm W that metataref flie sheet and the reinforcement is only about double thethiclc iterv a v is said; was li ear mea u ement ands: r n emement, at es he -Q @said- Pe forated Side,x% h1' I' DQ mI tss l lfi g a number ofperforations equa ltogsaid'multiprongs; alternately on: opposite sides thereof, 7

said prongs being spaced apartamliltipleef a nit ei 1inearmeasure nt inccmb m i with ashethavi ga r es o iperferations alongone side at uniform interval-1520f -said uniti ofwlinear m reimentandj rein e reinfemement surroundingonlyfthetwofinal perforations, the thicknessfiit the reinfome- -m ment: beingsuchkthat the total thickness 0f the sheet-and-the reinforcement is; only double the thicknessbfzthe sheet alone. is :14. an a. sprang tinder having its? :prongs spaced apart a multiple off'a' given unit of linear measurement, overlapping sheetsv each having a, "visihlfe' marginyeach sheet having a seriesof perforations adjacent one edge,

the perforations beingspaeed apart said git sen unitl'nf 'iinear measurement, in combina- 5. In. a prong binder =thavin-g its successive prongs spaced apart'a uniform'multiple of a given "unit. of llinear ineasu'rement, overlapping sheets each havinga-visiblemargin,'eaeh sheet having a series of 1 perforations adjacent one edge, the perforations being spaced 7 apart" said given innit oflinear," measurement; i'inl combii'iationj with; a; reinforcement surroundinga: few" of i'thelperforations near-.

7 :each end :of :the perforated side, the number of? perforationsa surrounded at 'each endibei-ngequalzto'said multiplei- V I. 6,In a prOng bindert-hauingi-lstaggemd 1 greatest th1ekness;therbundle haspn-lyeleveu prongs, overl pping sh shwing'a vi i e r margin, each sheet having a series of perforations adjacent one ed e, the perforations being spaced apart a uni orm unit of linear measurement from center to center, a prong from one side of the binder and more than two prongs from the other side of the binder adapted to be threaded into each sheet through several perforations, in combination with reinforcements at each end of each sheet at points surrounding the prong passing through the sheet nearest each end thereof.

7. A prong binder having successive 

